1. Field of the Invention
The present invention relates to apparatus and methods used in positioning and maintaining the position of devices used in catheter procedures within the human anatomy. The present invention includes steerable devices, locking mechanisms and rapid exchange technologies to minimize or eliminate movement of endoscopic instruments during endoscopic procedures.
2. Description of Related Art
Historically the migration of gallstones into an individual""s common bile duct was corrected by general surgical procedures. A surgeon would incise the bile duct and remove the gallstones and normally remove the gallbladder. In recent years less invasive treatment modalities have replaced these general surgical procedures and reduced patient trauma, long hospital stays and recovery periods.
For example, U.S. Pat. No. 4,696,668 and U.S. Pat. No. 4,781,677, both to Wilcox, disclose a treatment modality involving the administration of a dissolution agent in the bile duct to essentially dissolve any gallstones. More specifically, a catheter contains several lumens for inflating and deflating each of two balloons, venting bile, and infusing and aspirating the dissolution agent. Inflating the balloons occludes the bile duct at two spaced sites and creates a sealed spaced that receives the dissolution agent. As the space is sealed from the remaining biliary tree, the dissolution agent finds access to the gallbladder and any gallstones therein through the cystic duct with the exclusion of bile from the gallbladder fundus. The dissolution agent also will be confined in high concentration around bile duct gallstones. After the gallstones dissolve, the balloons are deflated and the catheter can be withdrawn. In this particular approach, the catheter is directed into the biliary tree using a standard duodenoscope that passes through the alimentary tract. Although this and analogous approaches have the potential of minimizing patient trauma, such treatments require extended placement of the duodenoscope in the patient, exhibit low efficacy and introduce a potential for adverse reactions to the dissolution agents.
In an alternative approach, a surgeon directs a surgical extractor into the biliary tree through at least an incision in the bile duct. For example, in U.S. Pat. No. 3,108,593 to Glassman a surgeon incises both the bile duct and duodenum. Then the surgeon directs an extractor through the bile duct incision, biliary tree, sphincter of Oddi and duodenum to exit through the duodenum incision. This extractor includes a series of longitudinally spaced cages for trapping any gallstones in the bile duct and removing them through either of the incisions.
U.S. Pat. No. 4,627,837 to Gonzalo discloses a catheter device with a pair of inflatable balloons at its distal end. This catheter is led through an incision in the bile duct toward the duodenum. After the distal balloon passes through the sphincter of Oddi, both balloons are expanded to anchor the catheter in place. This enables the catheter to be used for irrigating and flushing through other lumens in order to capture any gallstone in the second balloon for removal through the incised bile duct.
In accordance with still another modality as for the treatment of strictures, a surgeon may insert a catheter device through the bile duct or duodenum for the purpose of dilating or enlarging the sphincter of Oddi. For example, U.S. Pat. No. 4,705,041 to Kim discloses a dilator that is directed through an incision in the bile duct and the sphincter of Oddi. An expandable tip dilates the sphincter of Oddi. U.S. Pat. No. 5,035,696 to Rydell discloses an electrosurgical instrument that is directed through the duodenum and to the sphincter of Oddi for performing a sphincterotomy. This apparatus contains a cutting wire that is heated to cut the sphincter muscle. U.S. Pat. No. 5,024,617 to Karpiel, discloses a similar device that can be directed through a duodenoscope. U.S. Pat. No. 5,152,772 to Sewell, Jr. discloses a device for performing a sphincterotomy that is directed through an incision in the bile duct and includes a knife for cutting the sphincter muscle.
The use of the duodenoscope and sphincterotomy devices, such as shown in the Rydell and Karpiel patents, enables an internist to diagnose and treat problems in the biliary tree with less patient invasion then previously possible. For example, modalities as described in these patents eliminate the surgery needed for incising the bile duct. Consequently, these modalities can be performed as outpatient or day surgical procedures. These procedures greatly reduce patient trauma, the length of a hospital stay and recovery times.
The reduced patient trauma, hospital stays and recovery times has resulted in a growth in the number of endoscopic procedures performed for treating abnormal pathologies within the alimentary canal system and biliary tree (including the biliary, hepatic, and pancreatic ducts). The endoscope provides access to the general area of a desired duct using direct visualization. However, the duct itself must be navigated using a catheter in conjunction with fluoroscopy and guide wires.
Catheters are known for treatment of targeted anatomical regions. Known methods and devices for using biliary catheters for accessing the biliary tree for performing catheter procedures are disclosed in Weaver et al., U.S. Pat. No. 5,397,302 and Karpiel, U.S. Pat. No. 5,320,602, the disclosures of which are herein incorporated by reference. In general, for treatment of an abnormal pathology within a patient""s biliary tree, an endoscope is first introduced into the mouth of the patient. The endoscope includes a proximal end and a distal end, and has a lumen extending longitudinally between the proximal and distal ends. The endoscope is guided through the patient""s alimentary tract or canal until an opening at the distal end of the endoscope is proximate the area to receive treatment. At this point, the endoscope allows other components, such as a catheter, to access the targeted area.
For visualization or treatment within the biliary tree, the distal end of the endoscope is positioned proximate the papilla of vater leading to the common bile duct and the pancreatic duct. A catheter is guided through the lumen of the endoscope until a distal tip of the catheter emerges from the opening at the distal end of the endoscope.
The catheter may be used for accessing the biliary tree. The distal end of the catheter is guided through the orifice to the papilla of vater (located near the sphincter of Oddi) leading to the common bile duct and the pancreatic duct. A guide wire may be used in conjunction with the catheter to facilitate accessing a desired location within the biliary tree. The guide wire is inserted in an opening at a proximal end of the catheter and guided through the catheter until it emerges from the distal end of the catheter.
If visualization of the common bile duct is desired, the guide wire is guided into the common bile duct. The catheter is advanced over the guide wire until the distal end of the catheter is positioned in the common bile duct at the desired location. The catheter is now in position for delivery of contrast media for fluoroscopic visualization of anatomical detail within the common bile duct.
Visualization may reveal selected areas within the common bile duct that require treatment. To treat the selected areas, a different catheter is typically required, necessitating a catheter exchange. A catheter exchange typically involves removing the first catheter from the endoscope over the guide wire, and advancing a second catheter over the guide wire to the desired treatment site. Thus, once the guide wire is in place relative to the targeted area, it is highly desirable to maintain the position of the guide wire during subsequent catheter procedures, including during a catheter exchange procedure. If the guide wire moves during such a procedure, the guide wire may have to be re-directed through the body ducts to the target site, which is often a difficult, time consuming and tedious task.
In addition to performing a catheter exchange procedure, it may also be desirable to perform a guide wire exchange procedure. This may be desirable when, for example, a first guide wire is too large to fit through a desired body duct, or otherwise lacks the desired characteristics. Under these circumstances, a physician may leave the catheter in place, withdraw the first guide wire from the catheter, and insert a second guide wire through the catheter to the desired site. During this procedure, the catheter guides the guide wire to the desired site. Thus, once the catheter is positioned at a target site, it is highly desirable to maintain the position of the catheter during a guide wire exchange procedure so that the second guide wire may be guided directly to the desired site in a minimum amount of time.
For example, if an internist determines that gallstones are present in the biliary tree, particularly the common bile duct, the internist can insert a duodenoscope into the duodenum to view the sphincter of Oddi. Then a first catheter can be advanced through the working channel of the duodenoscope with or without a guidewire and directed through the sphincter of Oddi into the biliary tree. Contrast agent injected through the catheter enables fluoroscopy or other imaging procedures to confirm the presence of gallstones within the biliary tree. Next the internist exchanges the first catheter for a second catheter for performing a sphincterotomy such as the types disclosed in the above-identified Rydell and Karpiel patents. The second catheter is then exchanged for a third catheter such as shown in the Glassman patent or some other equivalent retrieval catheter for drawings gallstones through the enlarged sphincter of Oddi. Thereafter the retrieval catheter is manipulated to release the gallstone into the duodenum. The catheter, any guidewire and the duodenoscope can then be removed to complete the procedure.
This procedure is significantly less traumatic to the patient than other prior art procedures because the only incision occurs during the sphincterotomy. However, this procedure, as described above, requires three separate catheters and two catheter exchanges. These exchanges are required because the first, second and third catheters function solely to inject contrast agent to perform the sphincterotomy and to dislodge gallstones, respectively. The time required for performing each catheter exchange can increase patient trauma and increase the duration of the procedure and reduce efficiency. Moreover, each such procedure requires the use of two or three separate catheter devices.
Multi-lumen catheters are available which typically reduce the number of catheters and catheter exchanges used during a procedure and thereby reduce both the time required and the patient""s trauma while increasing efficiency. A common problem today concerns the accurate placement of an endoscopic instrument such as a cutting device. Secondly, once the cutting device, such as a sphincterotome, Ultratome, Rapid Exchange, Fluortome, Papilitome or similar device is properly positioned, the position of the device must be maintained during the cutting procedure. An example of a common problem with these devices is that after the device is positioned and left unattended xe2x80x9cset relaxationxe2x80x9d occurs in which the bow of a cutting instrument undesirably relaxes or straightens out without operator interaction.
Even with multi-lumen catheters, exchanges may be required. To maintain the position of a guide wire and/or catheter during an exchange, a physician typically must grasp the proximal end of the guide wire and/or catheter with one hand, and performing the corresponding exchange with the other. This is difficult, and often results in the movement of the guide wire and/or catheter.
In general, a need exists for an apparatus and method for accurate positioning of endoscopic instruments, such as cutting devices, and the maintenance of the position of the device.
Therefore, this invention provides an apparatus for, and a method of, accurate positioning of endoscopic instruments. Accurate positioning of the instruments is accomplished through the inclusion of a steering ability within the device. After the endoscopic instrument is properly positioning, the present invention uses rapid exchange technology, soft locks, and mechanical locks to maintain the position of the endoscopic instrument. Rapid exchange technology is used to minimize displacement forces present on the guidewire or catheters. Soft locks and mechanical locks resist movements caused by displacement forces.
The present invention includes an apparatus for use in a treatment modality including an enlargement procedure to be performed within a patient. In this embodiment the apparatus includes a catheter for being directed through internal passageways in the patient, and the catheter has a proximal end and a distal end. A proximal portion is adjacent to the proximal end and a distal portion is adjacent to the distal end. The catheter includes a first and at least a second generally parallel lumen, which extend between the proximal and the distal portions. The present invention includes a cutting wire for performing the enlargement procedure extending through the second lumen for operating at the distal portion in response to manipulations at the proximal end. The cutting wire has a distal end attached to the catheter at the distal end of the second lumen. A portion of the cutting wire is external to the catheter along a length coextensive with a portion of the distal portion of the catheter. The catheter also includes a handle for operating the cutting wire from a point proximal of the catheter. A rotatable coupling attaches the handle to the catheter and allows the handle to rotate relative to the proximal end of the catheter while engaging and rotating a proximal end of the cutting wire. The rotation of the handle causes the distal portion of the catheter to rotate. The present invention also includes a locking mechanism for locking an orientation of a distal portion of the cutting wire.
This embodiment of the present invention may further include a rotation lock which inhibits further rotation of the handle relative to the proximal end of the catheter and a rotation indicator configured to indicate an amount of rotation of the handle relative to the proximal end of the catheter. The rotation indicator may include a visual indicator of the amount of rotation and the visual indicator may include an index marking and a corresponding scale marking providing an indication of the amount of rotation. The rotation indicator may also include a device providing an audible indication in response to the rotation of the handle relative to the proximal end of the catheter. The locking mechanism of the present invention may include an insert positioned between moving parts of the apparatus to resist movement between the moving parts, or an insert which a guidewire passes through the insert and the insert resists movement of the guidewire. The locking mechanism may include evenly spaced detents in a handle body which interact with one or more pawls located in an active cord insert to resist movement of the active cord insert with respect to the handle body.
In another embodiment of the present invention the invention includes a method of cutting tissue in a body passage including selecting a catheter having a first lumen configured for receiving a wire guide and a second lumen configured for receiving an electrosurgical cutting wire. The catheter is positioned in the passage at a desired position using an endoscope and the electrosurgical cutting wire is actuated in the second lumen. In this embodiment the invention includes orientating the electrosurgical cutting wire by rotating a handle relative to a proximal end of the catheter and fixing an orientation of the electrosurgical cutting wire. The orientation of the electrosurgical cutting wire may be fixed by an insert which creates friction between moving parts in the catheter which resists movement between the moving parts. The orientation may also be fixed with detents which interact with pawls to resist movement between an active cord insert and a handle.
Another embodiment of the present invention includes a catheter handle comprising a rotatable coupling configured to allow free rotation of a proximal end of a catheter and a clamping member configured to engage a proximal end of a device extending through a lumen formed in the catheter whereby rotation of the handle causes rotation of a proximal end of the device in the lumen and a locking mechanism configured to resist movement in a distal end of the device. In this embodiment the device may include a cutting wire extending from the proximal end of the catheter to and connecting to a distal end of the catheter. A rotation lock may also be included which is engageable to inhibit a rotation of the handle with respect to the proximal end of the catheter.
Another embodiment of the present invention includes a catheter including a shaft having a proximal end and a distal end. The catheter includes a guidewire lumen carried by the shaft extending from a location proximal the distal end of the shaft to a location proximate the distal end of the shaft. Also included is a cutting device extending from the proximal end of the catheter to a distal portion of the catheter and where a distal portion of the cutting device is exterior to the catheter. In this embodiment means for accessing the guidewire lumen from a location exterior to the catheter shaft, located distal the proximal end of the shaft are included. These means include a first opening through the wall of the catheter shaft into the guidewire lumen located proximal the distal end of the shaft and a second opening through the wall of the shaft located proximal the first opening. Also included is a channel which gives access to the guide wire lumen extending longitudinally between the first opening and the second opening. Additionally, means for locking an orientation of the cutting device are also included. In this embodiment the guidewire lumen may be formed integral to the shaft. Additionally, the channel may include an opening extending longitudinally between the first opening and the second opening in communication with the guidewire lumen. The locking means may include an insert positioned between moving parts used to actuate the cutting device wherein the insert resists movement between the moving parts. The locking means may also include detents located in a handle of the catheter and at least one pawl located on an active cord insert where the active cord insert moves with respect to the handle and the detents cooperate with the pawl to resist movement of the active cord insert.
Another embodiment of the present invention includes a method of positioning a cutting device including a shaft having a proximal end and a distal end, within a patient""s lumen comprising the steps of: providing a guidewire lumen within the catheter, extending from a location proximal the distal end of the shaft to a location proximate the distal end of the shaft and providing a port through a sidewall of the shaft into the guidewire lumen, the port located distal of the proximal end of the shaft. In this embodiment a guidewire is moved through the port, relative to the shaft and the catheter is advanced over the guidewire. The cutting device is actuated so as to expose a distal portion of the cutting device exterior of the catheter and the orientation of the cutting device is fixed.